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ETUDE DU “POINT BRILLANT” SUR MODELES SISMIQUES*
- Source: Geophysical Prospecting, Volume 13, Issue 3, Jul 1965, p. 405 - 432
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- 27 Apr 2006
Abstract
Abstract
The technique of two‐dimensional seismic models offers a simple solution to the problem of pulse reflection at the interface of two solids. Particular attention is paid to the existence and character of the amplitude increase in the interference zone between PP and PPP. The following points are discussed:
- 1) – the considerable deformation of the pulse when such an increase exists.
- 2) – the desagreement existing in the neighborhood of the critical points between the amplitude calculated by plane wave theory and the amplitude observed for cylindrical or spherical waves.
- 3) – the nonexistence of such an increase when velocity or density contrasts are too great.
- 4) – the presence, in the case of very large velocity contrasts, of an increase of the amplitude in the zone of interference, between PP and PSP‐waves.
- 5) – the considerable importance of conversion arrivals (PS+SP).
- 6) – the necessity of taking into account the emission of distorsional waves so that the observed arrivals of conversion waves can be explained.